Human epidermal growth factor receptor 2 positive rates in invasive lobular breast carcinoma: The Singapore experience

Table 3 Univariate and multivariate Cox proportional hazard regression analysis for breast cancer-specific survival among all 864 invasive lobular carcinomas patients

Characteristics	Univariate analysis			Multivariate analysis
	HR	95%CI	P value	HR	95%CI		P value
Age (reference: ≤ 50 yr)
> 50 yr	2.16	1.53-3.05	< 0.001
Ethnicity (reference: Chinese)			< 0.0011				0.0041
Indian	2.60	1.63-4.14	< 0.001	2.55	1.28-5.05		0.008
Malay	0.89	0.43-1.82	0.744	1.07	0.43-2.67		0.885
Others	0.32	0.10-1.02	0.054	0.19	0.04-0.84		0.028
ER (reference: Negative)
Positive	0.72	0.42-1.26	0.255
PR (reference: Negative)
Positive	0.61	0.42-0.88	0.008	0.40	0.23-0.70		0.001
HER2 (reference: Negative)
Positive	2.08	1.32-3.26	0.002
Molecular subtype (reference: Luminal A)			0.0111				0.0041
Basal	1.49	0.72-3.07	0.281	1.16	0.36-3.77		0.801
HER2+	2.34	0.95-5.74	0.064	3.74	1.26-11.09		0.018
Luminal B	2.08	1.26-3.44	0.004	2.79	1.44-5.37		0.002
Tumour size (reference: ≤ 2 cm)
> 2 cm	2.76	1.53-4.97	< 0.001
Tumour stage (reference: Stage 1)			< 0.0011				< 0.001
Stage 2	3.11	1.09-8.92	0.034	2.19	0.74-6.49		0.159
Stage 3	13.02	4.89-34.68	< 0.001	6.49	2.35-17.89		< 0.001
Stage 4	117.79	43.5-317.87	< 0.001	56.27	18.44-171.68		< 0.001
Tumor grade (reference: Grade 1)			< 0.0011				0.0011
Grade 2	1.89	0.96-3.75	0.066	1.63	0.78-3.44		0.196
Grade 3	7.10	3.44-14.64	< 0.001	4.16	1.80-9.62		0.001
Chemotherapy (reference: No)
Yes	1.23	0.84-1.80	0.290
Surgery (reference: No)
Yes	0.06	0.04-0.08	< 0.001	0.23	0.11-0.51		< 0.001
Radiotherapy (reference: No)
Yes	0.94	0.65-1.37	0.758

¹Refers to type 3 P value. HR: Hazard ratio; CI: Confidence interval; HER2: Human epidermal growth factor receptor 2; ER: Estrogen receptor; PR: Progesterone receptor; HER2+: Human epidermal growth factor receptor 2 positive.